[Technical field]
[0001] The disclosure relates to a light emitting device, and more particularly, to a light
emitting device in which a plurality of light emitting layers are stacked.
[Related art]
[0002] Light emitting diodes as inorganic light sources are being diversely used in various
fields such as display devices, vehicle lamps and general lighting. Light emitting
diodes are rapidly replacing existing light sources due to their longer lifetime,
lower power consumption, and faster response speed than existing light sources.
[0003] In particular, a display device generally implements various colors by utilizing
mixed colors of blue, green and red. Each pixel of a display device includes blue,
green and red sub pixels, the color of a particular pixel is determined through the
colors of these sub pixels, and an image is implemented by a combination of pixels.
[0004] Light emitting diodes have been mainly used as backlight sources in display devices.
However, recently, a micro LED display has been developed as a next generation display
which directly implements images by using light emitting diodes.
[DISCLOSURE]
[Technical Problem]
[0005] The invention is directed to a light emitting device which is improved in light efficiency.
[0006] An object to be achieved by the disclosure is not limited to the aforementioned objects,
and those skilled in the art to which the disclosure pertains may clearly understand
other objects from the following descriptions.
[Technical Solution]
[0007] A light emitting device according to embodiments of the invention for solving the
technical problem may include: a first light emitting part including a first first-type
semiconductor layer, a first active layer and a first second-type semiconductor layer;
a second light emitting part disposed over the first light emitting part, and including
a second first-type semiconductor layer, a second active layer and a second second-type
semiconductor layer; a third light emitting part disposed over the second light emitting
part, and including a third first-type semiconductor layer, a third active layer and
a third second-type semiconductor layer; a first conductive pattern including a first
portion which is disposed in the second light emitting part and is electrically coupled
with at least one among the first first-type, first second-type, second first-type
and second second-type semiconductor layers, and a second portion which extends from
the first portion to one surface of the second light emitting part between the second
and third light emitting parts; and a second conductive pattern disposed in the third
light emitting part, and electrically coupled with the first conductive pattern, wherein
the second conductive pattern includes an area which overlaps at least partially with
the second portion of the first conductive pattern.
[0008] According to embodiments, the second light emitting part may have a via hole passing
through at least a portion of the second light emitting part; and the first portion
of the first conductive pattern may be formed along the via hole, and an inside of
the via hole may be filled with an insulating material.
[0009] According to embodiments, the third light emitting part may have a via hole passing
through the third light emitting part; the second conductive pattern may include a
first portion which is formed along the via hole of the third light emitting part,
and a second portion which extends from the first portion to one surface of the third
light emitting part; and the second portion of the first conductive pattern and the
first portion of the second conductive pattern may partially overlap with each other.
[0010] According to embodiments, the first portion of the first conductive pattern and the
first portion of the second conductive pattern may have the same width.
[0011] According to embodiments, the light emitting device may further include a pad electrically
coupled with the second portion of the second conductive pattern.
[0012] According to embodiments, the second light emitting part may have a via hole passing
through at least a portion of the second light emitting part, and the first portion
of the first conductive pattern may fill the via hole.
[0013] According to embodiments, the third light emitting part may have a via hole passing
through the third light emitting part; the second conductive pattern may include a
first portion which fills the via hole of the third light emitting part, and a second
portion which extends from the first portion onto one surface of the third light emitting
part; and the second portion of the first conductive pattern and the first portion
of the second conductive pattern may include at least partial areas which overlap
with each other.
[0014] According to embodiments, the first portion of the first conductive pattern and the
first portion of the second conductive pattern may have the same width.
[0015] According to embodiments, the light emitting device may further include a pad electrically
coupled with the second portion of the second conductive pattern.
[0016] According to embodiments, the first portion of the first conductive pattern may be
electrically coupled with the first first-type semiconductor layer, and the second
portion may be electrically coupled with the second first-type semiconductor layer
on the one surface of the second light emitting part; and the second conductive pattern
may include a first portion which is electrically coupled with the second portion
of the first conductive pattern, and a second portion which extends from the first
portion of the second conductive pattern and is electrically coupled with the third
first-type semiconductor layer.
[0017] According to embodiments, the first portion of the first conductive pattern may be
electrically coupled with the first second-type semiconductor layer; and the second
conductive pattern may include a first portion which is electrically coupled with
the second portion of the first conductive pattern, and a second portion which extends
from the first portion of the second conductive pattern to one surface of the third
light emitting part.
[0018] According to embodiments, the first portion of the first conductive pattern may be
electrically coupled with the second second-type semiconductor layer; and the second
conductive pattern may include a first portion which is electrically coupled with
the second portion of the first conductive pattern, and a second portion which extends
from the first portion of the second conductive pattern to one surface of the third
light emitting part.
[0019] According to embodiments, the light emitting device may further include a third conductive
pattern electrically coupled with the third second-type semiconductor layer.
[0020] According to embodiments, the third light emitting part may have a via hole passing
through at least a portion of the third light emitting part; and the third conductive
pattern may include a first portion which is disposed along the via hole, and a second
portion which extends from the first portion to one surface of the third light emitting
part.
[0021] According to embodiments, the light emitting device may further include a pad electrically
coupled with the second portion of the third conductive pattern.
[0022] According to embodiments, the third light emitting part may have a via hole passing
through at least a portion of the third light emitting part; and the third conductive
pattern may include a first portion which fills the via hole, and a second portion
which extends from the first portion to one surface of the third light emitting part.
[0023] According to embodiments, each of the first to third light emitting parts may have
an inclined outer sidewall.
[0024] According to embodiments, may further include an insulating layer disposed between
the first portion of the first conductive pattern and a side surface of the second
light emitting part.
[0025] According to embodiments, the insulating layer may extend to an outer sidewall of
the second light emitting part.
[0026] According to embodiments, the light emitting device may further include a first adhesion
part bonding the first and second light emitting parts; and a second adhesion part
bonding the second and third light emitting parts, wherein the first adhesion part
may extend to an outer sidewall of the first light emitting part, and wherein the
second adhesion part may extend to an outer sidewall of the second light emitting
part.
[0027] According to embodiments, the light emitting device may further include an insulating
layer extending to an outer sidewall of the first portion of the first conductive
pattern and an outer sidewall of the second light emitting part, wherein the insulating
layer may be disposed between the second light emitting part and the second adhesion
part.
[0028] According to embodiments, each of the first and second light emitting parts may have
an inclined outer sidewall; the first adhesion part may have a width that increases
from the first light emitting part toward the second light emitting part; and the
second adhesion part may have a width that increases from the second light emitting
part toward the third light emitting part.
[0029] The details of other embodiments are included in the detailed description and the
drawings.
[Advantageous effects]
[0030] In the light emitting device in accordance with embodiments of the disclosure, by
forming via holes in each of a plurality of light emitting parts and forming conductive
patterns which at least partially fill the via holes and extend to portions of each
light emitting part, it is possible to electrically couple conductive patterns with
a first pad, a second pad, a third pad and a common pad more stably than when via
holes are formed at a time after all light emitting parts are stacked.
[0031] Further, since each of the plurality of light emitting parts is isolated while forming
via holes, a tensile stress to be applied to a substrate may be mitigated.
[Description of Drawings]
[0032] FIG. 1a is a representation of an example of a top view to assist in the explanation
of a light emitting device in accordance with an embodiment of the disclosure.
[0033] FIGS. 1b and 1c are cross-sectional views taken along the line A-A' of FIG. 1a.
[0034] FIGS. 2 to 16 are representations of examples of cross-sectional views to assist
in the explanation of a method for manufacturing a light emitting device in accordance
with an embodiment of the disclosure.
[0035] FIGS. 17 and 18 are representations of examples of cross-sectional views to assist
in the explanation of a method for mounting light emitting devices to a mounting board
in accordance with an embodiment of the disclosure.
[Best Mode]
[0036] In order to understand the configuration and effect of the disclosure sufficiently,
embodiments of the disclosure will be described with reference to the accompanying
drawings. However, the disclosure is not limited to the embodiments set forth herein
and may be implemented in various forms, and a variety of changes may be added.
[0037] As used in the embodiments of the disclosure, a technical term may be interpreted
as a meaning conventionally known to those of ordinary skill in the art unless defined
otherwise.
[0038] Hereinafter, a light emitting device will be described below with reference to the
accompanying drawings through various examples of embodiments.
[0039] FIG. 1a is a representation of an example of a top view to assist in the explanation
of a light emitting device in accordance with an embodiment of the disclosure, and
FIGS. 1b and 1c are cross-sectional views taken along the line A-A' of FIG. 1a.
[0040] Referring to FIGS. 1a to 1c, a light emitting device may include a first light emitting
part LE1, a second light emitting part LE2 and a third light emitting part LE3.
[0041] One surface of the first light emitting part LE1 may face the second light emitting
part LE2, and the other, opposing surface of the first light emitting part LE1 facing
away from the one surface may be the light extraction surface of the light emitting
device. In this case where the other surface of the first light emitting part LE1
is the light extraction surface, the wavelength of the light emitted from the first
light emitting part LE1 may be the shortest, the wavelength of the light emitted from
the second light emitting part LE2 may be longer than the wavelength of the light
emitted from the first light emitting part LE1 and be shorter than the wavelength
of the light emitted from the third light emitting part LE3, and the wavelength of
the light emitted from the third light emitting part LE3 may be the longest. For example,
the first light emitting part LE1 may emit blue light, the second light emitting part
LE2 may emit green light, and the third light emitting part LE3 may emit red light.
[0042] In an embodiment of the invention, the first light emitting part LE1 and the second
light emitting part LE2 may be stacked in different order from those described above.
For example, in the above-described embodiment, the second light emitting part LE2
is stacked on the first light emitting part LE1, however the first light emitting
part LE1 may be stacked on the second light emitting part LE2 in this embodiment.
In this case, one surface of the second light emitting part LE2 may face the first
light emitting part LE1, and the other, opposing surface of the second light emitting
part LE2 opposite to the surface of the second light emitting part LE2 may be a light
extraction surface of the light emitting device.
[0043] The first light emitting part LE1 may include a first n-type semiconductor layer
102, a first active layer 104, a first p-type semiconductor layer 106 and a first
ohmic layer 108 which are vertically stacked. The second light emitting part LE2 may
include a second ohmic layer 208, a second p-type semiconductor layer 206, a second
active layer 204 and a second n-type semiconductor layer 202 which are vertically
stacked. The third light emitting part LE3 may include a third ohmic layer 308, a
third p-type semiconductor layer 306, a third active layer 304 and a third n-type
semiconductor layer 302 which are vertically stacked.
[0044] Each of the first n-type semiconductor layer 102, the second n-type semiconductor
layer 202 and the third n-type semiconductor layer 302 may be a Si-doped gallium nitride-based
semiconductor layer. Each of the first p-type semiconductor layer 106, the second
p-type semiconductor layer 206 and the third p-type semiconductor layer 306 may be
a Mg-doped gallium nitride-based semiconductor layer. Each of the first active layer
104, the second active layer 204 and the third active layer 304 may include a multi-quantum
well (MQW), and the composition ratio thereof may be determined to emit light of a
desired peak wavelength. As each of the first ohmic layer 108, the second ohmic layer
208 and the third ohmic layer 308, a transparent conductive oxide (TCO) such as zinc
oxide (ZnO), indium oxide (InO
2), tin oxide (SnO), indium tin zinc oxide (ITZO), and indium tin oxide (ITO) may be
used. Or, as each of the first ohmic layer 108, the second ohmic layer 208 and the
third ohmic layer 308, a metal ohmic layer formed of a metal such as Al, Ti, Cr, Ni,
Au, Ag, Sn, W, Cu, or an alloy thereof may be used, without being limited thereto.
The alloy of the metal may be an alloy of Au-Be, Au-Te or Au-Ge. According to an embodiment,
the first light emitting part LE1 may have a first hole HL1 which exposes the first
n-type semiconductor layer 102. For instance, the first hole HL1 may have a vertical
side surface. For another instance, the first hole HL1 may have an inclined side surface.
[0045] The light emitting device may further include a first conductive pattern CP1 which
is brought into electrical contact with the first n-type semiconductor layer 102 exposed
by the first hole HL1 of the first light emitting part LE1 and a second conductive
pattern CP2 which is brought into electrical contact with the first ohmic layer 108.
Each of the first conductive pattern CP1 and the second conductive pattern CP2 may
include at least one selected from the group consisting of Au, Ag, Ni, Al, Rh, Pd,
Ir, Ru, Mg, Zn, Pt, Hf, Cr, Ti and Cu. Further, each of the first conductive pattern
CP1 and the second conductive pattern CP2 may include an alloy thereof. Selectively,
the first conductive pattern CP1 and the second conductive pattern CP2 may be omitted.
[0046] The first light emitting part LE1 may be disposed by being separated from the second
light emitting part LE2. For instance, the first ohmic layer 108 of the first light
emitting part LE1 and the second ohmic layer 208 of the second light emitting part
LE2 may be disposed to face each other. For another instance, the first ohmic layer
108 of the first light emitting part LE1 and the second n-type semiconductor layer
202 of the second light emitting part LE2 may be disposed to face each other.
[0047] The light emitting device may further include a first adhesion part AD1 which bonds
the first light emitting part LE1 and the second light emitting part LE2, between
the first light emitting part LE1 and the second light emitting part LE2 separated
from each other. The first adhesion part AD1 may be transparent and have an insulating
property and an adhesion property. The first adhesion part AD1 may include glass,
a polymer, a resist or a polyimide. For example, the first adhesion part AD1 may include
SOG (spin-on-glass), BCB (benzo cyclo butadiene), HSQ (hydrogen silsesquioxanes),
PMMA (polymethylmethacrylate), parylene,an SU-8 photoresist, or etc. According to
an embodiment, the first adhesion part AD1 may be disposed while filling the first
hole HL1 of the first light emitting part LE1.
[0048] According to an embodiment, the first light emitting part LE1 may have an inclined
side surface such that it has a wider width in a downward direction. That is to say,
the first n-type semiconductor layer 102 of the first light emitting part LE1 may
have a larger width than the first ohmic layer 108, the first ohmic layer 108 may
have a larger width than the first p-type semiconductor layer 106, and the first p-type
semiconductor layer 106 may have a larger width than the first ohmic layer 108. The
first adhesion part AD1 may extend to surround the outer sidewall of the first light
emitting part LE1.
[0049] Selectively, the light emitting device may further include a first color filter which
is disposed between the first light emitting part LE1 and the second light emitting
part LE2. For instance, the first color filter may be disposed on the first ohmic
layer 108 of the first light emitting part LE1. For another instance, the first color
filter may be disposed on the second ohmic layer 208 of the second light emitting
part LE2. The first color filter may reflect the light generated from the first light
emitting part LE1 and pass the light generated from the second light emitting part
LE2 and the third light emitting part LE3, so that the light generated from the first
light emitting part LE1 does not exert an influence on each of the second light emitting
part LE2 and the third light emitting part LE3. The first color filter may include
a DBR (distributed Bragg reflector) having a structure in which TiO2 and SiO2 are
alternately stacked.
[0050] The second light emitting part LE2 may include a second hole HL2 which passes through
the second light emitting part LE2 and the first adhesion part AD1 and exposes the
second conductive pattern CP2, a third hole HL3 which exposes the second ohmic layer
208 of the second light emitting part LE2, and a fourth hole HL4 which passes through
the second light emitting part LE2 and the first adhesion part AD1 and exposes the
first conductive pattern CP1. For instance, the second light emitting part LE2 may
further include a fifth hole HL5 which exposes the second n-type semiconductor layer
202 as a portion of the second n-type semiconductor layer 202 is etched. The fifth
hole HL5 may be selectively formed, and may be omitted as the case may be.
[0051] Selectively, in the case where the first conductive pattern CP1 and the second conductive
pattern CP2 are omitted, the second hole HL2 may expose a portion of the first ohmic
layer 108, and the fourth hole HL4 may expose a portion of the first n-type semiconductor
layer 102 in the first hole HL1.
[0052] According to an embodiment, each of the second hole HL2, the third hole HL3, the
fourth hole HL4 and the fifth hole HL5 may have an inclined side surface of which
width gradually decreases in the downward direction. A width WT of each of the second
hole HL2, the third hole HL3, the fourth hole HL4 and the fifth hole HL5 may have
substantially the same size. The width WT of each hole is the largest width of the
hole. For example, the width WT of each of the second hole HL2, the third hole HL3,
the fourth hole HL4 and the fifth hole HL5 may be approximately 1/10 of the size of
the light emitting device.
[0053] The light emitting device may further include a third conductive pattern CP3 which
at least partially fills the second hole HL2, is brought into electrical contact with
the second conductive pattern CP2 and extends onto the second light emitting part
LE2, a fourth conductive pattern CP4 which at least partially fills the third hole
HL3, is brought into electrical contact with the second ohmic layer 208 and extends
onto the second light emitting part LE2, and a fifth conductive pattern CP5 which
at least partially fills the fourth hole HL4 and the fifth hole HL5, is brought into
electrical contact with the first conductive pattern CP1 and extends onto the second
light emitting part LE2. Each of the third conductive pattern CP3, the fourth conductive
pattern CP4 and the fifth conductive pattern CP5 may include at least one selected
from the group consisting of Au, Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Hf, Cr, Ti
and Cu. Further, each of the third conductive pattern CP3, the fourth conductive pattern
CP4 and the fifth conductive pattern CP5 may include an alloy thereof.
[0054] Selectively, in the case where the first conductive pattern CP1 and the second conductive
pattern CP2 are omitted, the third conductive pattern CP3 may be brought into electrical
contact with the first ohmic layer 108 exposed at the bottom of the second hole HL2,
and the fifth conductive pattern CP5 may be brought into electrical contact with the
first n-type semiconductor layer 102 exposed at the bottom of the fourth hole HL4.
[0055] According to an embodiment shown in FIG. 1b, the third conductive pattern CP3 may
not completely fill the second hole HL2, and may be thinly and conformally formed
along the inner sidewall of the second hole HL2. The third conductive pattern CP3
may include a first portion CP3_1 which is disposed in the second hole HL2 and a second
portion CP3_2 which extends from the first portion CP3_1 to the top surface of the
second light emitting part LE2. The fourth conductive pattern CP4 may not completely
fill the third hole HL3, and may be thinly and conformally formed along the inner
sidewall of the third hole HL3. The fourth conductive pattern CP4 may include a first
portion CP4_1 which is disposed in the third hole HL3 and a second portion CP4_2 which
extends from the first portion CP4_1 to the top surface of the second light emitting
part LE2. The fifth conductive pattern CP5 may not completely fill the fourth hole
HL4 and the fifth hole HL5, and may be thinly and conformally formed along the inner
sidewalls of the fourth hole HL4 and the fifth hole HL5. The fifth conductive pattern
CP5 may include first portions CP5_1 which are respectively disposed in the fourth
hole HL4 and the fifth hole HL5 and a second portion CP5_2 which couples the first
portions CP5_1 and extends from the first portions to the top surface of the second
light emitting part LE2. For instance, the second portion CP5_2 of the fifth conductive
pattern CP5 may be disposed between the fourth hole HL4 and the fifth hole HL5. However,
it is to be noted that the disclosure is not limited thereto.
[0056] According to another embodiment shown in FIG. 1c, the third conductive pattern CP3
may include a first portion CP3_1 which fills the second hole HL2 and a second portion
CP3_2 which extends from the first portion CP3_1 and extends on the top surface of
the second light emitting part LE2. The fourth conductive pattern CP4 may include
a first portion CP4_1 which fills the third hole HL3 and a second portion CP4_2 which
extends from the first portion CP4_1 and extends on the top surface of the second
light emitting part LE2. The fifth conductive pattern CP5 may include first portions
CP5_1 which fill the fourth hole HL4 and the fifth hole HL5 and a second portion CP5_2
which couples the first portions CP5_1 and extends from the first portions CP5_1 to
the top surface of the second light emitting part LE2.
[0057] The light emitting device may further include a first passivation layer PVT1 which
surrounds the outer sidewall of the third conductive pattern CP3 between the third
conductive pattern CP3 and the second hole HL2, surrounds the outer sidewall of the
fourth conductive pattern CP4 between the fourth conductive pattern CP4 and the third
hole HL3, surrounds the outer sidewall of the fifth conductive pattern CP5 between
the fifth conductive pattern CP5 and the fourth hole HL4 and the fifth hole HL5, and
extends to the top surface of the second light emitting part LE2 to insulate the third
conductive pattern CP3, the fourth conductive pattern CP4 and the fifth conductive
pattern CP5 from the second light emitting part LE2. The first passivation layer PV1
may include at least one selected from the group consisting of SiNx, TiNx, TiOx, TaOx,
ZrOx, HfOx, AlxOy and SiOx.
[0058] According to an embodiment, the second light emitting part LE2 may have an inclined
side surface such that it has a wider width in the downward direction. That is to
say, the second ohmic layer 208 of the second light emitting part LE2 may be larger
than the second p-type semiconductor layer 206, the second p-type semiconductor layer
206 may be larger than the second active layer 204, and the second active layer 204
may be larger than the second n-type semiconductor layer 202. A second adhesion part
AD2 may extend to surround the outer sidewall of the second light emitting part LE2.
The first passivation layer PV1 may be disposed between the outer sidewall of the
second light emitting part LE2 and the second adhesion part AD2. In another instance,
the first passivation layer PV1 may be omitted between the outer sidewall of the second
light emitting part LE2 and the second adhesion part AD2.
[0059] The second light emitting part LE2 may be disposed by being separated from the third
light emitting part LE3. For instance, the second n-type semiconductor layer 202 of
the second light emitting part LE2 and the second ohmic layer 208 of the third light
emitting part LE3 may be disposed to face each other. For another instance, the second
n-type semiconductor layer 202 of the second light emitting part LE2 and the third
n-type semiconductor layer 302 of the third light emitting part LE3 may be disposed
to face each other.
[0060] The light emitting device may further include the second adhesion part AD2 which
bonds the second light emitting part LE2 and the third light emitting part LE3, between
the second light emitting part LE2 and the third light emitting part LE3 separated
from each other. The second adhesion part AD2 may be transparent and have an insulating
property and an adhesion property. The second adhesion part AD2 may include the same
material as the first adhesion part AD1, such as glass, a polymer, a resist or a polyimide.
For example, the second adhesion part AD2 may include SOG, BCB, HSQ or an SU-8 photoresist,
etc. According to the embodiment shown in FIG. 1b, the second adhesion part AD2 may
be disposed while filling the second hole HL2 formed with the third conductive pattern
CP3, the third hole formed with the fourth conductive pattern CP4 and the fourth hole
HL4 and the fifth hole HL5 formed with the fifth conductive pattern CP5.
[0061] Meanwhile, selectively, the light emitting device may further include a second color
filter which is disposed between the second light emitting part LE2 and the third
light emitting part LE3. For instance, the second color filter may be disposed on
the third ohmic layer 308. The second color filter may reflect the light generated
from each of the first light emitting part LE1 and the second light emitting part
LE2 and pass the light generated from the third light emitting part LE3, so that the
light generated from the first light emitting part LE1 and the second light emitting
part LE2 does not exert an influence on the third light emitting part LE3. The second
color filter may include a DBR having a structure in which TiO2 and SiO2 are alternately
stacked. For example, the alternation sequence or number of TiO2 and SiO2 in the second
color filter may be different from the alternation sequence or number of TiO2 and
SiO2 in the first color filter.
[0062] The third light emitting part LE3 may include a sixth hole HL6 which passes through
the third light emitting part LE3 and the second adhesion part AD2 and exposes the
third conductive pattern CP3, a seventh hole HL7 which exposes the third ohmic layer
308 of the third light emitting part LE3, an eighth hole which passes through the
third light emitting part LE3 and the second adhesion part AD2 and exposes the fourth
conductive pattern CP4, and a ninth hole which passes through the third light emitting
part LE3 and the second adhesion part AD2 and exposes the fifth conductive pattern
CP5. For instance, the third light emitting part LE3 may further include a tenth hole
HL10 which exposes the third n-type semiconductor layer 302 as a portion of the third
n-type semiconductor layer 302 is etched. The tenth hole HL10 may be selectively formed,
and may be omitted as the case may be.
[0063] The sixth hole HL6 may expose the second portion CP3_2 of the third conductive pattern
CP3, the eighth hole HL8 may expose the second portion CP4_2 of the fourth conductive
pattern CP4, and the ninth hole HL9 may expose the second portion CP5_2 of the fifth
conductive pattern CP5. As shown, the second portion CP3_2 of the third conductive
pattern CP3, the second portion CP4_2 of the fourth conductive pattern CP4 and the
second portion CP5_2 of the fifth conductive pattern CP5 may be positioned on the
same plane as they extend on the top surface of the second light emitting part LE2.
Thus, the sixth hole HL6, the eighth hole HL8 and the ninth hole HL9 may have substantially
the same height.
[0064] According to an embodiment, each of the sixth hole HL6, the seventh hole HL7, the
eighth hole HL8, the ninth hole HL9 and the tenth hole HL10 may have an inclined side
surface of which width gradually decreases in the downward direction. A width WT of
each of the sixth hole HL6, the seventh hole HL7, the eighth hole HL8, the ninth hole
HL9 and the tenth hole HL10 may have substantially the same size. The width WT of
each of the sixth hole HL6, the seventh hole HL7, the eighth hole HL8, the ninth hole
HL9 and the tenth hole HL10 may be substantially the same as the width of each of
the second hole HL2, the third hole HL3, the fourth hole HL4 and the fifth hole HL5.
For example, the width WT of each of the sixth hole HL6, the seventh hole HL7, the
eighth hole HL8, the ninth hole HL9 and the tenth hole HL10 may be approximately 1/10
of the size of the light emitting device.
[0065] The light emitting device may further include a sixth conductive pattern CP6 which
at least partially fills the sixth hole HL6, is brought into electrical contact with
the second portion of the third conductive pattern CP3 and extends onto the third
light emitting part LE3, a seventh conductive pattern CP7 which at least partially
fills the seventh hole HL7, is brought into electrical contact with the third ohmic
layer 308 and extends onto the third light emitting part LE3, an eighth conductive
pattern CP8 which at least partially fills the eighth hole HL8, is brought into electrical
contact with the second portion of the fourth conductive pattern CP4 and extends onto
the third light emitting part LE3, and a ninth conductive pattern CP9 which at least
partially fills the ninth hole HL9 and the tenth hole HL10, is brought into electrical
contact with the second portion of the fifth conductive pattern CP5 and extends onto
the third light emitting part LE3. Each of the sixth conductive pattern CP6, the seventh
conductive pattern CP7, the eighth conductive pattern CP8 and the ninth conductive
pattern CP9 may include at least one selected from the group consisting of Au, Ag,
Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Hf, Cr, Ti and Cu. Further, each of the sixth
conductive pattern CP6, the seventh conductive pattern CP7, the eighth conductive
pattern CP8 and the ninth conductive pattern CP9 may include an alloy thereof.
[0066] According to an embodiment, the sixth conductive pattern CP6 may be electrically
coupled with the third conductive pattern CP3, the third conductive pattern CP3 may
be electrically coupled with the second conductive pattern CP2, and the second conductive
pattern CP2 may be electrically coupled with the first ohmic layer 108. By this fact,
the sixth conductive pattern CP6 may be electrically coupled with the first ohmic
layer 108 of the first light emitting part LE1. The seventh conductive pattern CP7
may be electrically coupled with the third ohmic layer 308 of the third light emitting
part LE3. The eighth conductive pattern CP8 may be electrically coupled with the fourth
conductive pattern CP4, and the fourth conductive pattern CP4 may be electrically
coupled with the second ohmic layer 208. By this fact, the eight conductive pattern
CP8 may be electrically coupled with the second ohmic layer 208 of the second light
emitting part LE2. The ninth conductive pattern CP9 may be electrically coupled with
the third n-type semiconductor layer 302 and the fifth conductive pattern CP5, the
fifth conductive pattern CP5 may be electrically coupled with the second n-type semiconductor
layer 202 and the first conductive pattern CP1, and the first conductive pattern CP1
may be electrically coupled with the first n-type semiconductor layer 102. By this
fact, the ninth conductive pattern CP9 may be electrically coupled in common with
the first n-type semiconductor layer 102, the second n-type semiconductor layer 202
and the third n-type semiconductor layer 302.
[0067] According to the embodiment shown in FIG. 1b, the sixth conductive pattern CP6 may
not completely fill the sixth hole HL6, and may be thinly and conformally formed along
the inner sidewall of the sixth hole HL6. The sixth conductive pattern CP6 may include
a first portion CP6_1 which is disposed in the sixth hole HL6 and a second portion
CP6_2 which extends from the first portion CP6_1 to the top surface of the third light
emitting part LE3. The seventh conductive pattern CP7 may not completely fill the
seventh hole HL7, and may be thinly and conformally formed along the inner sidewall
of the seventh hole HL7. The seventh conductive pattern CP7 may include a first portion
CP7_1 which is disposed in the seventh hole HL7 and a second portion CP7_2 which extends
from the first portion CP7_1 to the top surface of the third light emitting part LE3.
The eighth conductive pattern CP8 may not completely fill the eighth hole HL8, and
may be thinly and conformally formed along the inner sidewall of the eighth hole HL8.
The eighth conductive pattern CP8 may include a first portion CP8_1 which is disposed
in the eighth hole HL8 and a second portion CP8_2 which extends from the first portion
CP8_1 to the top surface of the third light emitting part LE3. The ninth conductive
pattern CP9 may not completely fill the ninth hole HL9 and the tenth hole HL10, and
may be thinly and conformally formed along the inner sidewalls of the ninth hole HL9
and the tenth hole HL10. The ninth conductive pattern CP9 may include first portions
CP9_1 which are respectively disposed in the ninth hole HL9 and the tenth hole HL10
and a second portion CP9_2 which couples the first portions CP9_1 between the first
portions CP9_1 and extends to the top surface of the third light emitting part LE3.
The second portion CP9_2 of the ninth conductive pattern CP9 may be disposed between
the ninth hole HL9 and the tenth hole HL10. However, it is to be noted that the disclosure
is not limited thereto.
[0068] According to another embodiment shown in FIG. 1c, the sixth conductive pattern CP6
may include a first portion CP6_1 which fills the sixth hole HL6 and a second portion
CP6_2 which extends from the first portion CP6_1 and extends on the top surface of
the third light emitting part LE3. The seventh conductive pattern CP7 may include
a first portion CP7_1 which fills the seventh hole HL7 and a second portion CP7_2
which extends from the first portion CP7_1 and extends on the top surface of the third
light emitting part LE3. The eighth conductive pattern CP8 may include a first portion
CP8_1 which fills the eighth hole HL8 and a second portion CP8_2 which extends from
the first portion CP8_1 and extends on the top surface of the third light emitting
part LE3. The ninth conductive pattern CP9 may include first portions CP9_1 which
respectively fill the ninth hole HL9 and the tenth hole HL10 and a second portion
CP9_2 which couples the first portions CP9_1, extends from the first portions CP9-1
and extends on the top surface of the third light emitting part LE3.
[0069] The light emitting device may further include a second passivation layer PVT2 which
surrounds the outer sidewall of the sixth conductive pattern CP6 between the sixth
conductive pattern CP6 and the sixth hole HL6, surrounds the outer sidewall of the
seventh conductive pattern CP7 between the seventh conductive pattern CP7 and the
seventh hole HL7, surrounds the outer sidewall of the eighth conductive pattern CP8
between the eighth conductive pattern CP8 and the eighth hole HL8, surrounds the outer
sidewall of the ninth conductive pattern CP9 between the ninth conductive pattern
CP9 and the ninth hole HL9 and the tenth hole HL10, and extends to the top surface
of the third light emitting part LE3 to insulate the sixth conductive pattern CP6,
the seventh conductive pattern CP7, the eighth conductive pattern CP8 and the ninth
conductive pattern CP9 from the third light emitting part LE3. The second passivation
layer PVT2 may include the same material as the first passivation layer PVT1. For
example, the second passivation layer PVT2 may include at least one selected from
the group consisting of SiNx, TiNx, TiOx, TaOx, ZrOx, HfOx, AlxOy, and SiOx.
[0070] According to an embodiment, the third light emitting part LE3 may have an inclined
side surface such that it has a wider width in the downward direction. That is to
say, the third ohmic layer 308 of the third light emitting part LE3 may be larger
than the third p-type semiconductor layer 306, the third p-type semiconductor layer
306 may be larger than the third active layer 304, and the third active layer 304
may be larger than the third n-type semiconductor layer 302. The second passivation
layer PVT2 may extend to surround the outer sidewall of the third light emitting part
LE3.
[0071] The light emitting device may further include a first pad PD1 which is brought into
electrical contact with the sixth conductive pattern CP6 on the sixth conductive pattern
CP6 electrically coupled with the first ohmic layer 108, a second pad PD2 which is
brought into electrical contact with the eighth conductive pattern CP8 on the eighth
conductive pattern CP8 electrically coupled with the second ohmic layer 208, a third
pad PD3 which is brought into electrical contact with the seventh conductive pattern
CP7 on the seventh conductive pattern CP7 electrically coupled with the third ohmic
layer 308, and a common pad CPD which is brought into electrical contact with the
ninth conductive pattern CP9 on the ninth conductive pattern CP9 electrically coupled
with the first n-type semiconductor layer 102, the second n-type semiconductor layer
202 and the third n-type semiconductor layer 302. Each of the first pad PD1, the second
pad PD2, the third pad PD3 and the common pad CPD may include at least one selected
from the group consisting of Au, Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Hf, Cr, Ti
and Cu. Further, each of the first pad PD1, the second pad PD2, the third pad PD3
and the common pad CPD may include an alloy thereof.
[0072] According to an embodiment, in the case where the light emitting device has a quadrangular
structure when viewed from the top, the first pad PD1, the second pad PD2, the third
pad PD3 and the common pad CPD may be respectively disposed at corner portions of
the light emitting device. For instance, the first pad PD1 may be disposed at a first
corner CN1, the second pad PD2 may be disposed at a third corner CN3, the third pad
PD3 may be disposed at a second corner CN2, and the common pad CPD may be disposed
at a fourth corner CN4.
[0073] The light emitting device may further include a third passivation layer PVT3 which
covers the other portions except the first pad PD1, the second pad PD2, the third
pad PD3 and the common pad CPD on the third light emitting part LE3. The third passivation
layer PVT3 may include the same material as the first passivation layer PVT1 or the
second passivation layer PVT2. For example, the third passivation layer PVT3 may include
at least one selected from the group consisting of SiNx, TiNx, TiOx, TaOx, ZrOx, HfOx,
AlxOy and SiOx. According to an embodiment, the second passivation layer PV2 may be
disposed between the outer sidewall of the third light emitting part LE3 and the third
passivation layer PVT3. In another instance, the second passivation layer PV2 may
be omitted between the outer sidewall of the third light emitting part LE3 and the
third passivation layer PVT3.
[0074] In the example shown in FIG. 1b, the third passivation layer PVT3 may be conformally
formed on the second passivation layer PVT2 in such a way as not to completely fill
the sixth hole HL6, the seventh hole HL7, the eighth hole HL8, the ninth hole HL9
and the tenth hole HL10 formed with the sixth conductive pattern CP6, the seventh
conductive pattern CP7, the eighth conductive pattern CP8 and the ninth conductive
pattern CP9. Unlike this, the third passivation layer PVT3 may be formed in such a
way as to fill the sixth hole HL6, the seventh hole HL7, the eighth hole HL8, the
ninth hole HL9 and the tenth hole HL10 formed with the sixth conductive pattern CP6,
the seventh conductive pattern CP7, the eighth conductive pattern CP8 and the ninth
conductive pattern CP9.
[0075] In another example shown in FIG. 1c, the third passivation layer PVT3 may be formed
on the top surfaces of the sixth conductive pattern CP6, the seventh conductive pattern
CP7, the eighth conductive pattern CP8 and the ninth conductive pattern CP9 and on
the second passivation layer PVT2.
[0076] In the light emitting device described above, in the second light emitting part LE2
and the first adhesion part AD1, the second hole HL2 which exposes the second conductive
pattern CP2 electrically coupled with the first ohmic layer 108, the third hole HL3
which exposes the second ohmic layer 208, the fourth hole HL4 which exposes the first
conductive pattern CP1 electrically coupled with the first n-type semiconductor layer
102 and the fifth hole HL5 which exposes the second n-type semiconductor layer 202
may be formed, and the third conductive pattern CP3, the fourth conductive pattern
CP4 and the fifth conductive pattern CP5 which at least partially fill the second
hole HL2, the third hole HL3, the fourth hole HL4 and the fifth hole HL5 may be disposed.
Further, in the third light emitting part LE3 and the second adhesion part AD2, the
sixth hole HL6 which exposes the third conductive pattern CP3, the seventh hole HL7
which exposes the third ohmic layer 308, the eighth hole HL8 which exposes the fourth
conductive pattern CP4, the ninth hole HL9 which exposes the fifth conductive pattern
CP5 and the tenth hole HL10 which exposes the third n-type semiconductor layer 302
may be formed, and the sixth conductive pattern CP6, the seventh conductive pattern
CP7, the eighth conductive pattern CP8 and the ninth conductive pattern CP9 which
at least partially fill the sixth hole HL6, the seventh hole HL7, the eighth hole
HL8, the ninth hole HL9 and the tenth hole HL10 may be disposed. In this way, conductive
patterns electrically coupled with the first light emitting part LE1 may be disposed
in the second light emitting part LE2 and the first adhesion part AD1, and conductive
patterns electrically coupled with the conductive patterns coupled with the first
light emitting part LE1 may be separately disposed in the third light emitting part
LE3 and the second adhesion part AD2. Therefore, the first pad PD1 may be electrically
stably coupled with the first ohmic layer 108 through the third conductive pattern
CP3 and the second conductive pattern CP2 along the sixth conductive pattern CP6.
The second pad PD2 may be electrically stably coupled with the second ohmic layer
208 through the fourth conductive pattern CP4 along the eighth conductive pattern
CP8. The third pad PD3 may be electrically stably coupled with the third ohmic layer
308 through the seventh conductive pattern CP7. Further, the common pad CPD may be
electrically stably coupled with the third n-type semiconductor layer 302 through
the ninth conductive pattern CP9, with the second n-type semiconductor layer 202 through
the fifth conductive pattern CP5 along the ninth conductive pattern CP9, and with
the first n-type semiconductor layer 102 through the first conductive pattern CP1
along the fifth conductive pattern CP5.
[0077] Meanwhile, in a light emitting device, processes are performed on a substrate which
is made of a material such as sapphire, and, while the processes are performed, a
tensile stress may be induced so that a warpage phenomenon in which the center portion
of the substrate warps downward occurs. In this regard, in the embodiment of the disclosure,
the first adhesion part AD1 and the second adhesion part AD2 may mitigate the tensile
stress applied to the substrate.
[0078] Moreover, as will be described in detail in a subsequent manufacturing method, the
first light emitting part LE1 is isolated while the first hole HL1 is formed, the
second light emitting part LE2 is isolated while the second hole HL2, the third hole
HL3, the fourth hole HL4 and the fifth hole HL5 are formed, and the third light emitting
part LE3 is isolated while the sixth hole HL6, the seventh hole HL7, the eighth hole
HL8, the ninth hole HL9 and the tenth hole HL10 are formed, whereby it is possible
to further mitigate the tensile stress applied to the substrate.
[0079] Hereafter, a method for manufacturing the light emitting device of FIGS. 1a and 1b
will be described.
[0080] FIGS. 2 to 16 are representations of examples of cross-sectional views to assist
in the explanation of a method for manufacturing a light emitting device in accordance
with an embodiment of the disclosure.
[0081] Referring to FIG. 2, a first n-type semiconductor layer 102, a first active layer
104, a first p-type semiconductor layer 106 and a first ohmic layer 108 may be sequentially
formed on a first substrate 100, and thereby, a first light emitting part LE1 may
be formed.
[0082] The first substrate 100 as a substrate capable of growing a gallium nitride-based
semiconductor layer may include a sapphire (Al2O3), a silicon carbide (SiC), a gallium
nitride (GaN), an indium gallium nitride (InGaN), an aluminum gallium nitride (AlGaN),
an aluminum nitride (AlN), a gallium oxide (Ga2O3), a gallium arsenic (GaAs) or silicon
(Si). Also, the first substrate 100 may be a flexible substrate or a substrate which
is formed with a circuit.
[0083] The first n-type semiconductor layer 102, the first active layer 104 and the first
p-type semiconductor layer 106 may be sequentially formed on the first substrate 100
by using a growing method such as MOCVD (metal organic chemical vapor deposition),
MBE (molecular beam epitaxy), HVPE (hydride vapor phase epitaxy) and MOC (metal-organic
chloride).
[0084] The first ohmic layer 108 may be formed on the first p-type semiconductor layer 106
through a chemical vapor deposition (CVD) process or a physical vapor deposition (PVD).
[0085] Referring to FIG. 3, by etching the first ohmic layer 108, the first p-type semiconductor
layer 106 and the first active layer 104, a first hole HL1 may be formed in the first
light emitting part LE1. The etching process may etch a top portion of the first n-type
semiconductor layer 102.
[0086] After forming the first hole HL1, by etching the first ohmic layer 108, the first
p-type semiconductor layer 106, the first active layer 104 and the first n-type semiconductor
layer 102, the first light emitting part LE1 may be isolated.
[0087] In this way, by isolating the first light emitting part LE1, a tensile stress to
be applied to the first substrate 100 may be reduced.
[0088] Referring to FIG. 4, a first conductive pattern CP1 and a second conductive pattern
CP2 may be respectively formed in the first light emitting part LE1. The first conductive
pattern CP1 may be formed in the first hole HL1 by being separated from the inner
sidewall of the first hole HL1. The second conductive pattern CP2 may be formed on
the first ohmic layer 108.
[0089] For instance, after forming a conductive layer on the top surface of the first light
emitting part LE1 formed with the first hole HL1, the first conductive pattern CP1
and the second conductive pattern CP2 may be respectively formed through a patterning
process generally known in the art.
[0090] Referring to FIG. 5, a second n-type semiconductor layer 202, a second active layer
204, a second p-type semiconductor layer 206 and a second ohmic layer 208 may be sequentially
formed on a second substrate 200, and thereby, a second light emitting part LE2 may
be formed.
[0091] The second substrate 200 as a substrate capable of growing a gallium nitride-based
semiconductor layer may include a sapphire (Al2O3), a silicon carbide (SiC), a gallium
nitride (GaN), an indium gallium nitride (InGaN), an aluminum gallium nitride (AlGaN),
an aluminum nitride (AlN), a gallium oxide (Ga2O3), a gallium arsenic (GaAs) or silicon
(Si). Also, the second substrate 200 may be a flexible substrate or a substrate which
is formed with a circuit.
[0092] The second n-type semiconductor layer 202, the second active layer 204 and the second
p-type semiconductor layer 206 may be sequentially formed on the second substrate
200 by using a growing method such as MOCVD, MBE, HVPE and MOC.
[0093] The second ohmic layer 208 may be formed on the second p-type semiconductor layer
206 through a CVD or PVD process.
[0094] Referring to FIG. 6, by turning over the second substrate 200, the first ohmic layer
108 of the first light emitting part LE1 and the second ohmic layer 208 of the second
light emitting part LE2 may be disposed to face each other, and the first light emitting
part LE1 and the second light emitting part LE2 may be bonded with each other through
a first adhesion part AD1.
[0095] For instance, after the first adhesion part AD1 is formed on the first light emitting
part LE1 to fill the first hole HL1 formed with the first conductive pattern CP1 and
the second ohmic layer 208 is disposed to face the first ohmic layer 108, by curing
the first adhesion part AD1 through a thermal process, the first light emitting part
LE1 and the second light emitting part LE2 may be bonded with each other.
[0096] In this case, the first light emitting part LE1 may be surrounded by the first adhesion
part AD1, and the first adhesion part AD1 may be a protective layer that protects
the side surface of the first light emitting part LE1.
[0097] After the first light emitting part LE1 and the second light emitting part LE2 are
bonded with each other by the first adhesion part AD1, the second substrate 200 may
be removed through a laser lift-off (LLO) process.
[0098] Referring to FIG. 7, by etching the second light emitting part LE2 and the first
adhesion part AD1, a second hole HL2 which exposes the second conductive pattern CP2,
a third hole HL3 which exposes the second ohmic layer 208, a fourth hole HL4 which
exposes the first conductive pattern CP1 and a fifth hole HL5 which exposes a portion
of the second n-type semiconductor layer 202 may be formed. Selectively, the fifth
hole HL5 may not be formed.
[0099] Each of the second hole HL2, the third hole HL3, the fourth hole HL4 and the fifth
hole HL5 may have the same width WT. Each of the second hole HL2, the third hole HL3,
the fourth hole HL4 and the fifth hole HL5 may have an inclined side surface of which
width gradually decreases in a downward direction.
[0100] While forming the second hole HL2, the third hole HL3, the fourth hole HL4 and the
fifth hole HL5, by etching the second n-type semiconductor layer 202, the second active
layer 204, the second p-type semiconductor layer 206 and the first ohmic layer 108,
the second light emitting part LE2 may be isolated.
[0101] In this way, by isolating the second light emitting part LE2, a tensile stress to
be applied to the substrate 100 may be reduced. In addition, the second light emitting
part LE2 has a tapered side surface. In other words, the second light emitting part
LE2 has a shape in which an area of the second light emitting part LE2 gradually decreases
toward an upper direction from the substrate 100.
[0102] Referring to FIG. 8, a first passivation layer PV1 may be formed on the inner sidewalls
of the second hole HL2, the third hole HL3, the fourth hole HL4 and the fifth hole
HL5 and on the top surface of the second n-type semiconductor layer 202.
[0103] For instance, the first passivation layer PV1 may be conformally formed on the second
light emitting part LE2 and the first adhesion part AD1 formed with the second hole
HL2, the third hole HL3, the fourth hole HL4 and the fifth hole HL5, in such a way
as not to completely fill the second hole HL2, the third hole HL3, the fourth hole
HL4 and the fifth hole HL5. As each of the second hole HL2, the third hole HL3, the
fourth hole HL4 and the fifth hole HL5 has an inclined side surface, it may be easy
to conformally form the first passivation layer PV1. Then, the first passivation layer
PV1 which is formed on the bottoms of the second hole HL2, the third hole HL3, the
fourth hole HL4 and the fifth hole HL5 may be removed.
[0104] The first passivation layer PV1 may remain on the outer sidewall of the second light
emitting part LE2. Unlike this, the first passivation layer PV1 may be removed from
the outer sidewall of the second light emitting part LE2.
[0105] Referring to FIG. 9, a third conductive pattern CP3, a fourth conductive pattern
CP4 and a fifth conductive pattern CP5 which at least partially fill the second hole
HL2, the third hole HL3, the fourth hole HL4 and the fifth hole HL5 formed with the
first passivation layer PV1 may be respectively formed.
[0106] For instance, by using a deposition process, a first conductive layer (not shown)
may be conformally formed on the first passivation layer PV1 in such a way as not
to completely fill the second hole HL2, the third hole HL3, the fourth hole HL4 and
the fifth hole HL5 formed with the first passivation layer PV1. As described above,
since each of the second hole HL2, the third hole HL3, the fourth hole HL4 and the
fifth hole HL5 has an inclined side surface, it may be easy to conformally form the
first conductive layer. In succession, the third conductive pattern CP3 which is electrically
coupled with the first conductive pattern CP1 and at least partially fills the second
hole HL2, the fourth conductive pattern CP4 which is electrically coupled with the
second ohmic layer 208 and at least partially fills the third hole HL3, and the fifth
conductive pattern CP5 which is electrically coupled with the first conductive pattern
CP1, at least partially fills the fourth hole HL4, is electrically coupled with the
second n-type semiconductor layer 202 and at least partially fills the fifth hole
HL5 may be respectively formed.
[0107] The third conductive pattern CP3 may include a first portion CP3_1 which is formed
in the second hole HL2 and a second portion CP3_2 which extends from the first portion
CP3_1 onto the first passivation layer PV1 formed on the second n-type semiconductor
layer 202. The fourth conductive pattern CP4 may include a first portion CP4_1 which
is formed in the third hole HL3 and a second portion CP4_2 which extends from the
first portion CP4_1 onto the first passivation layer PV1 formed on the second n-type
semiconductor layer 202. The fifth conductive pattern CP5 may include first portions
CP5_1 which are respectively formed in the fourth hole HL4 and the fifth hole HL5
and a second portion CP5_2 which couples the first portions CP5_1 and extends onto
the first passivation layer PV1 formed on the second n-type semiconductor layer 202.
[0108] While it is illustrated and described in the present embodiment that the third conductive
pattern CP3, the fourth conductive pattern CP4 and the fifth conductive pattern CP5
are thinly and conformally formed in such a way as not to completely fill the second
hole HL2, the third hole HL3, the fourth hole HL4 and the fifth hole HL5, it is to
be noted that the third conductive pattern CP3, the fourth conductive pattern CP4
and the fifth conductive pattern CP5 may be formed in such a way as to fill the second
hole HL2, the third hole HL3, the fourth hole HL4 and the fifth hole HL5.
[0109] Referring to FIG. 10, a third n-type semiconductor layer 302, a third active layer
304, a third p-type semiconductor layer 306 and a third ohmic layer 308 may be sequentially
formed on a third substrate 300, and thereby, a third light emitting part LE3 may
be formed.
[0110] The third substrate 300 as a substrate capable of growing a gallium nitride-based
semiconductor layer may include a sapphire (Al2O3), a silicon carbide (SiC), a gallium
nitride (GaN), an indium gallium nitride (InGaN), an aluminum gallium nitride (AlGaN),
an aluminum nitride (AlN), a gallium oxide (Ga2O3), a gallium arsenic (GaAs) or silicon
(Si). Also, the third substrate 300 may be a flexible substrate or a substrate which
is formed with a circuit.
[0111] The third n-type semiconductor layer 302, the third active layer 304 and the third
p-type semiconductor layer 306 may be sequentially formed on the third substrate 300
by using a growing method such as MOCVD, MBE, HVPE and MOC.
[0112] The third ohmic layer 308 may be formed on the third p-type semiconductor layer 306
through CVD or PVD.
[0113] Referring to FIG. 11, by turning over the third substrate 300, the second n-type
semiconductor layer 202 of the second light emitting part LE2 and the third ohmic
layer 308 of the third light emitting part LE3 may be disposed to face each other,
and the second light emitting part LE2 and the third light emitting part LE3 may be
bonded to each other through a second adhesion part AD2.
[0114] For instance, after the second adhesion part AD2 is formed on the second light emitting
part LE2 to fill the second hole HL2, the third hole HL3, the fourth hole HL4 and
the fifth hole HL5 formed with the third conductive pattern CP3, the fourth conductive
pattern CP4 and the fifth conductive pattern CP5 and the third ohmic layer 308 is
disposed to face the second n-type semiconductor layer 202, by curing the second adhesion
part AD2 through a thermal process, the second light emitting part LE2 and the third
light emitting part LE3 may be bonded with each other.
[0115] In this case, the side of the second light emitting part LE2 may be surrounded by
the second adhesion part AD2, and the second adhesion part AD2 may be a protective
layer protecting the side of the second light emitting part LE2.
[0116] After the second light emitting part LE2 and the third light emitting part LE3 are
bonded with each other by the second adhesion part AD2, the third substrate 300 may
be removed through an LLO process.
[0117] Referring to FIG. 12, by etching the third light emitting part LE3 and the second
adhesion part AD2, a sixth hole HL6 which exposes the second portion of the third
conductive pattern CP3, a seventh hole HL7 which exposes the third ohmic layer 308,
an eighth hole HL8 which exposes the second portion of the fourth conductive pattern
CP4, a ninth hole HL9 which exposes the second portion of the fifth conductive pattern
CP5 and a tenth hole HL10 which exposes a portion of the third n-type semiconductor
layer 302 may be formed. Selectively, the tenth hole HL10 may not be formed.
[0118] Each of the sixth hole HL6, the seventh hole HL7, the eighth hole HL8, the ninth
hole HL9 and the tenth hole HL10 may have the same width WT. Each of the sixth hole
HL6, the seventh hole HL7, the eighth hole HL8, the ninth hole HL9 and the tenth hole
HL10 may have the same width WT as each of the second hole HL2, the third hole HL3,
the fourth hole HL4 and the fifth hole HL5. Each of the sixth hole HL6, the seventh
hole HL7, the eighth hole HL8, the ninth hole HL9 and the tenth hole HL10 may have
an inclined side surface of which width gradually decreases in the downward direction.
[0119] While forming the sixth hole HL6, the seventh hole HL7, the eighth hole HL8, the
ninth hole HL9 and the tenth hole HL10, by etching the third n-type semiconductor
layer 302, the third active layer 304, the third p-type semiconductor layer 306 and
the third ohmic layer 308, the third light emitting part LE3 may be isolated.
[0120] In this way, by isolating the third light emitting part LE3, a tensile stress to
be applied to the substrate 100 may be reduced.
[0121] Referring to FIG. 13, a second passivation layer PV2 may be formed on the inner sidewalls
of the sixth hole HL6, the seventh hole HL7, the eighth hole HL8, the ninth hole HL9
and the tenth hole HL10 and on the top surface of the third n-type semiconductor layer
302.
[0122] For instance, the second passivation layer PV2 may be conformally formed on the third
light emitting part LE3 and the second adhesion part AD2 formed with the sixth hole
HL6, the seventh hole HL7, the eighth hole HL8, the ninth hole HL9 and the tenth hole
HL10, in such a way as not to completely fill the sixth hole HL6, the seventh hole
HL7, the eighth hole HL8, the ninth hole HL9 and the tenth hole HL10. As each of the
sixth hole HL6, the seventh hole HL7, the eighth hole HL8, the ninth hole HL9 and
the tenth hole HL10 has an inclined side surface, it may be easy to conformally form
the second passivation layer PV2. Then, the second passivation layer PV2 formed on
the bottoms of the sixth hole HL6, the seventh hole HL7, the eighth hole HL8, the
ninth hole HL9 and the tenth hole HL10 may be removed.
[0123] The second passivation layer PV2 may remain on the outer sidewall of the third light
emitting part LE3. Unlike this, the second passivation layer PV2 may be removed from
the outer sidewall of the third light emitting part LE3.
[0124] Referring to FIG. 14, a sixth conductive pattern CP6, a seventh conductive pattern
CP7, an eighth conductive pattern CP8 and a ninth conductive pattern CP9 which at
least partially fill the sixth hole HL6, the seventh hole HL7, the eighth hole HL8,
the ninth hole HL9 and the tenth hole HL10 formed with the second passivation layer
PV2 may be respectively formed.
[0125] For instance, a second conductive layer (not shown) may be conformally formed on
the second passivation layer PV2 in such a way as not to completely fill the sixth
hole HL6, the seventh hole HL7, the eighth hole HL8, the ninth hole HL9 and the tenth
hole HL10 formed with the second passivation layer PV2. As described above, as each
of the sixth hole HL6, the seventh hole HL7, the eighth hole HL8, the ninth hole HL9
and the tenth hole HL10 has an inclined side surface, it may be easy to conformally
form the second conductive layer. In succession, through generally performing an etching
process for the second conductive layer, the sixth conductive pattern CP6 which is
electrically coupled with the second portion CP2_2 of the third conductive pattern
CP3 and at least partially fills the sixth hole HL6, the seventh conductive pattern
CP7 which is electrically coupled with the third ohmic layer 308 and at least partially
fills the seventh hole HL7, the eighth conductive pattern CP8 which is electrically
coupled with the second portion CP4_2 of the fourth conductive pattern CP4 and at
least partially fills the eighth hole HL8 and the ninth conductive pattern CP9 which
is electrically coupled with the second portion CP5_2 of the fifth portion and at
least partially fills the ninth hole HL9 and the tenth hole HL10 may be respectively
formed.
[0126] The sixth conductive pattern CP6 may include a first portion CP6_1 which is formed
in the sixth hole HL6 and a second portion CP6_2 which extends from the first portion
CP6_1 onto the second passivation layer PV2 formed on the third n-type semiconductor
layer 302. The seventh conductive pattern CP7 may include a first portion CP7_1 which
is formed in the seventh hole HL7 and a second portion CP7_2 which extends from the
first portion CP7_1 onto the second passivation layer PV2 formed on the third n-type
semiconductor layer 302. The eighth conductive pattern CP8 may include a first portion
CP8_1 which is formed in the eighth hole HL8 and a second portion CP8_2 which extends
from the first portion CP8_1 onto the second passivation layer PV2 formed on the third
n-type semiconductor layer 302. The ninth conductive pattern CP9 may include first
portions CP9_1 which are respectively formed in the ninth hole HL9 and the tenth hole
HL10 and a second portion CP9_2 which couples the first portions CP9_1 and extends
onto the second passivation layer PV2 formed on the third n-type semiconductor layer
302.
[0127] While it is illustrated and described in the present embodiment that the sixth conductive
pattern CP6, the seventh conductive pattern CP7, the eighth conductive pattern CP8
and the ninth conductive pattern CP9 are thinly and conformally formed in such a way
as not to completely fill the sixth hole HL6, the seventh hole HL7, the eighth hole
HL8, the ninth hole HL9 and the tenth hole HL10, it is to be noted that the sixth
conductive pattern CP6, the seventh conductive pattern CP7, the eighth conductive
pattern CP8 and the ninth conductive pattern CP9 may be formed in such a way as to
fill the sixth hole HL6, the seventh hole HL7, the eighth hole HL8, the ninth hole
HL9 and the tenth hole HL10.
[0128] Referring to FIG. 15, a third passivation layer PV3 may be conformally formed on
the sixth conductive pattern CP6, the seventh conductive pattern CP7, the eighth conductive
pattern CP8 and the ninth conductive pattern CP9 and on the second passivation layer
PV2. The third passivation layer PV3 may be thinly and conformally formed in such
a way as not to completely fill the sixth hole HL6, the seventh hole HL7, the eighth
hole HL8, the ninth hole HL9 and the tenth hole HL10 formed with the sixth conductive
pattern CP6, the seventh conductive pattern CP7, the eighth conductive pattern CP8
and the ninth conductive pattern CP9.
[0129] The third passivation layer PV3 may be formed on the second passivation layer PV2
which is formed on the outer sidewall of the third light emitting part LE3.
[0130] Referring to FIG. 16, a first pad PD1 which is electrically coupled with the sixth
conductive pattern CP6, a second pad PD2 which is electrically coupled with the eighth
conductive pattern CP8, a third pad PD3 which is electrically coupled with the seventh
conductive pattern CP7 and a common pad CPD which is electrically coupled with the
ninth conductive pattern CP9 may be respectively formed.
[0131] For instance, by etching the third passivation layer PV3, a first opening OP1 which
exposes the second portion CP6_2 of the sixth conductive pattern CP6, a second opening
OP2 which exposes the second portion CP8_2 of the eighth conductive pattern CP8, a
third opening OP3 which exposes the second portion CP7_2 of the seventh conductive
pattern CP7 and a third opening OP3 which exposes the second portion CP9_2 of the
ninth conductive pattern CP9 may be formed.
[0132] A third conductive layer (not shown) may be formed on the third passivation layer
PV3 in such a way as to fill the first opening OP1, the second opening OP2, the third
opening OP3 and the fourth opening OP4. Through generally performing an etching process
for the third conductive layer, the first pad PD1 which fills the first opening OP1
and is electrically coupled with the first ohmic layer 108 by being brought into electrical
contact with the sixth conductive pattern CP6, the second pad PD2 which fills the
second opening OP2 and is electrically coupled with the second ohmic layer 208 by
being brought into electrical contact with the eighth conductive pattern CP8, the
third pad PD3 which fills the third opening OP3 and is electrically coupled with the
third ohmic layer 308 by being brought into electrical contact with the seventh conductive
pattern CP7 and the common pad CPD which fills the fourth opening OP4 and is electrically
coupled in common with the third n-type semiconductor layer 302, the second n-type
semiconductor layer 202 and the first n-type semiconductor layer 102 by being brought
into electrical contact with the ninth conductive pattern CP9 may be formed.
[0133] According to the present embodiment, in the second light emitting part LE2 and the
first adhesion part AD1, the second hole HL2 which exposes the second conductive pattern
CP2 electrically coupled with the first ohmic layer 108, the third hole HL3 which
exposes the second ohmic layer 208, the fourth hole HL4 which exposes the first conductive
pattern CP1 electrically coupled with the first n-type semiconductor layer 102 and
the fifth hole HL5 which exposes the second n-type semiconductor layer 202 may be
formed. In another process, in the third light emitting part LE3 and the second adhesion
part AD2, the sixth hole HL6 which exposes the third conductive pattern CP3, the seventh
hole HL7 which exposes the third ohmic layer 308, the eighth hole HL8 which exposes
the fourth conductive pattern CP4, the ninth hole HL9 which exposes the fifth conductive
pattern CP5 and the tenth hole HL10 which exposes the third n-type semiconductor layer
302 may be formed. In this regard, in the case of forming, at a time, holes which
pass through the first light emitting part LE1, the second light emitting part LE2
and the third light emitting part LE3, difficulties exist when performing an etching
process, due to a problem caused in terms of aspect ratio. In the present embodiment,
since one etching process is performed in the second light emitting part LE2 and the
first adhesion part AD1 and another etching process is performed in the third light
emitting part LE3 and the second adhesion part AD2, it is possible to overcome the
difficulties.
[0134] Moreover, the third conductive pattern CP3, the fourth conductive pattern CP4 and
the fifth conductive pattern CP5 which are electrically coupled with the first light
emitting part LE1 may be disposed in the second light emitting part LE2 and the first
adhesion part AD 1, and the sixth conductive pattern CP6, the seventh conductive pattern
CP7, the eighth conductive pattern CP8 and the ninth conductive pattern CP9 which
are electrically coupled with the third conductive pattern CP3, the fourth conductive
pattern CP4 and the fifth conductive pattern CP5 coupled with the first light emitting
part LE1 may be separately disposed in the third light emitting part LE3 and the second
adhesion part AD2. Therefore, the first pad PD1 may be electrically stably coupled
with the first ohmic layer 108 through the third conductive pattern CP3 and the second
conductive pattern CP2 along the sixth conductive pattern CP6. The second pad PD2
may be electrically stably coupled with the second ohmic layer 208 through the fourth
conductive pattern CP4 along the eighth conductive pattern CP8. The third pad PD3
may be electrically stably coupled with the third ohmic layer 308 through the seventh
conductive pattern CP7. Further, the common pad CPD may be electrically stably coupled
with the third n-type semiconductor layer 302 through the ninth conductive pattern
CP9, with the second n-type semiconductor layer 202 through the fifth conductive pattern
CP5 along the ninth conductive pattern CP9, and with the first n-type semiconductor
layer 102 through the first conductive pattern CP1 along the fifth conductive pattern
CP5.
[0135] Hereafter, a method for mounting the light emitting device described above with reference
to FIGS. 2 to 16 onto a mounting board will be described.
[0136] FIGS. 17 and 18 are representations of examples of cross-sectional views to assist
in the explanation of a method for mounting light emitting devices to a mounting board
in accordance with an embodiment of the disclosure.
[0137] Referring to FIG. 17, a plurality of light emitting devices LED which are formed
through FIGS. 2 to 16 may be mounted to a target mounting board MB.
[0138] Bonding pads BPD which are to be electrically bonded with the first pad PD1, the
second pad PD2, the third pad PD3 and the common pad CPD, respectively, may be formed
on the mounting board MB Adhesion balls BL may be respectively formed on the bonding
pads BPD. Each of the adhesion balls BL may include In, Au, Sn, Cu, and the like.
Unlike this, adhesion balls BL may be formed on the first pad PD1, the second pad
PD2, the third pad PD3 and the common pad CPD.
[0139] The bonding pads BPD and the adhesion balls BL may be formed to correspond to positions
where the light emitting devices LED are to be mounted.
[0140] By turning over the first substrate 100 which is formed with the plurality of light
emitting devices LED, the light emitting devices LED may be positioned to face the
mounting board MB which is formed with the bonding pads BPD.
[0141] A mask pattern MSK having a hole which allows laser pass therethrough and is disposed
at a position corresponding to the light emitting devices LED to be separated from
the first substrate 100 may be provided on the turned-over first substrate 100. The
mask pattern MSK amy be omitted.
[0142] Referring to FIG. 18, by performing a selective laser lift-off (LLO) process for
the first substrate 100 through using the mask pattern MSK, the light emitting devices
LED which are disposed to face target mounting positions of the mounting board MB
may be separated from the first substrate 100. A separation distance between the separated
light emitting devices LED may be changed depending on the mounting board MB. When
the light emitting devices LED are separated from the first substrate 100 by irradiating
a laser onto the first substrate 100, a mask pattern MSK is provided on the first
substrate 100, thereby more precise irradiation of the laser may be performed on the
light emitting devices LEDs to be separated from the 100. However, if the laser can
be properly irradiated to the light emitting devices LEDs to be separated, the mask
pattern MSK may be omitted.
[0143] The first pad PD1, the second pad PD2, the third pad PD3 and the common pad CPD of
each of the separated light emitting devices LED may be respectively bonded with the
adhesion balls BL which are formed on the bonding pads BPD. By this fact, the light
emitting devices LED may be mounted to the mounting board MB
[0144] If all the light emitting devices LED are mounted at the target positions, the first
substrate 100 may be separated from the light emitting devices LED without separately
performing a process for removing the first substrate 100.
[0145] While various embodiments have been described above, it will be understood to those
skilled in the art that the embodiments described are by way of example only. Accordingly,
the disclosure described herein should not be limited based on the described embodiments.
1. A light emitting device comprising:
a first light emitting part including a first first-type semiconductor layer, a first
active layer and a first second-type semiconductor layer;
a second light emitting part disposed over the first light emitting part, and including
a second first-type semiconductor layer, a second active layer and a second second-type
semiconductor layer;
a third light emitting part disposed over the second light emitting part, and including
a third first-type semiconductor layer, a third active layer and a third second-type
semiconductor layer;
a first conductive pattern including a first portion which is disposed in the second
light emitting part and is electrically coupled with at least one among the first
first-type, first second-type, second first-type and second second-type semiconductor
layers, and a second portion which extends from the first portion to one surface of
the second light emitting part between the second and third light emitting parts;
and
a second conductive pattern disposed on the third light emitting part, and electrically
coupled with the first conductive pattern,
wherein the second conductive pattern includes an area which overlaps at least partially
with the second portion of the first conductive pattern.
2. The light emitting device according to claim 1,
wherein the second light emitting part has a via hole passing through at least a portion
of the second light emitting part, and
wherein the first portion of the first conductive pattern is formed along the via
hole, and an inside of the via hole is filled with an insulating material.
3. The light emitting device according to claim 2,
wherein the third light emitting part has a via hole passing through the third light
emitting part,
wherein the second conductive pattern includes a first portion which is formed along
the via hole of the third light emitting part, and a second portion which extends
from the first portion to one surface of the third light emitting part, and
wherein the second portion of the first conductive pattern and the first portion of
the second conductive pattern partially overlap with each other.
4. The light emitting device according to claim 3, wherein the first portion of the first
conductive pattern and the first portion of the second conductive pattern have the
same width.
5. The light emitting device according to claim 3, further comprising:
a pad electrically coupled with the second portion of the second conductive pattern.
6. The light emitting device according to claim 1,
wherein the second light emitting part has a via hole passing through at least a portion
of the second light emitting part, and
wherein the first portion of the first conductive pattern fills the via hole.
7. The light emitting device according to claim 6,
wherein the third light emitting part has a via hole passing through the third light
emitting part,
wherein the second conductive pattern includes a first portion which fills the via
hole of the third light emitting part, and a second portion which extends from the
first portion onto one surface of the third light emitting part, and
wherein the second portion of the first conductive pattern and the first portion of
the second conductive pattern include at least partial areas which overlap with each
other.
8. The light emitting device according to claim 7, wherein the first portion of the first
conductive pattern and the first portion of the second conductive pattern have the
same width.
9. The light emitting device according to claim 7, further comprising:
a pad electrically coupled with the second portion of the second conductive pattern.
10. The light emitting device according to claim 1,
wherein the first portion of the first conductive pattern is electrically coupled
with the first first-type semiconductor layer, and the second portion is electrically
coupled with the second first-type semiconductor layer on the one surface of the second
light emitting part, and
wherein the second conductive pattern includes a first portion which is electrically
coupled with the second portion of the first conductive pattern, and a second portion
which extends from the first portion of the second conductive pattern and is electrically
coupled with the third first-type semiconductor layer.
11. The light emitting device according to claim 1,
wherein the first portion of the first conductive pattern is electrically coupled
with the first second-type semiconductor layer, and
wherein the second conductive pattern includes a first portion which is electrically
coupled with the second portion of the first conductive pattern, and a second portion
which extends from the first portion of the second conductive pattern to one surface
of the third light emitting part.
12. The light emitting device according to claim 1,
wherein the first portion of the first conductive pattern is electrically coupled
with the second second-type semiconductor layer, and
wherein the second conductive pattern includes a first portion which is electrically
coupled with the second portion of the first conductive pattern, and a second portion
which extends from the first portion of the second conductive pattern to one surface
of the third light emitting part.
13. The light emitting device according to claim 1, further comprising: a third conductive
pattern electrically coupled with the third second-type semiconductor layer.
14. The light emitting device according to claim 13,
wherein the third light emitting part has a via hole passing through at least a portion
of the third light emitting part, and
wherein the third conductive pattern includes a first portion which is disposed along
the via hole, and a second portion which extends from the first portion to one surface
of the third light emitting part.
15. The light emitting device according to claim 14, further comprising:
a pad electrically coupled with the second portion of the third conductive pattern.
16. The light emitting device according to claim 13,
wherein the third light emitting part has a via hole passing through at least a portion
of the third light emitting part, and
wherein the third conductive pattern includes a first portion which fills the via
hole, and a second portion which extends from the first portion to one surface of
the third light emitting part.
17. The light emitting device according to claim 1, wherein each of the first to third
light emitting parts has an inclined outer sidewall.
18. The light emitting device according to claim 1, further comprising:
an insulating layer disposed between the first portion of the first conductive pattern
and a side surface of the second light emitting part.
19. The light emitting device according to claim 18, wherein the insulating layer extends
to an outer sidewall of the second light emitting part.
20. The light emitting device according to claim 1, further comprising:
a first adhesion part bonding the first and second light emitting parts; and
a second adhesion part bonding the second and third light emitting parts,
wherein the first adhesion part extends to an outer sidewall of the first light emitting
part, and
wherein the second adhesion part extends to an outer sidewall of the second light
emitting part.
21. The light emitting device according to claim 20, further comprising:
an insulating layer extending to an outer sidewall of the first portion of the first
conductive pattern and an outer sidewall of the second light emitting part,
wherein the insulating layer is disposed between the second light emitting part and
the second adhesion part.
22. The light emitting device according to claim 20,
wherein each of the first and second light emitting parts has an inclined outer sidewall,
wherein the first adhesion part has a width that increases from the first light emitting
part toward the second light emitting part, and
wherein the second adhesion part has a width that increases from the second light
emitting part toward the third light emitting part.